(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY(PCT)
`
` T (
`
`(19) World Intellectual Property Organization
`International Bureau
`
`(43) International Publication Date
`10 April 2003 (10.04.2003)
`
`(1) International Patent Classification’:
`F24D 17/00, E03B 7/04
`
`PC
`
`(10) International Publication Number
`WO 03/029721 Al
`
`F17D 1/14,
`
`74)
`
`Agent: BAILEY WALSH & CO; 5 York Place, Leeds
`LS1 2SD (GB).
`
`Q1) International Application Number:
`
`=PCT/GB02/04148
`
`(81)
`
`(22) International Filing Date:
`12 September 2002 (12.09.2002)
`
`(25) Filing Language:
`
`(26) Publication Language:
`
`English
`
`English
`
`Designated States (national): AE, AG, AL, AM, AI, AU,
`AZ, BA, BB, BG, BR, BY, BZ, CA, CH, CN, CR, CU, CZ,
`DE, DK, DM, DZ, EC, EE, ES, FI, GB, GD, GE, GH, GM,
`HR, HU,ID,IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK,
`LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX,
`MZ, NO, NZ, PH, PL, PT, RO, RU, SD, SE, SG, SI, SK,
`SL, TJ, TM, TR, TT, TZ, UA, UG, US, UZ, VN, YU, ZA,
`ZM, ZW.
`
`(30) Priority Data:
`0123340.2
`0129813.2
`
`28 September 2001 (28.09.2001)
`13 December 2001 (13.12.2001)
`
`GB
`GB
`
`(71) Applicant (for all designated States except US): HONEY-
`MAN WATER LIMITED [GB/GB]; Harmire Enterprise
`Park, Barnard Castle, County Durham DL12 8BN (GB).
`
`(84)
`
`Designated States (regional): ARIPO patent (GH, GM,
`KE, LS, MW, MZ, SD, SL, SZ, TZ, UG, ZM, ZW),
`Eurasian patent (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM),
`European patent (AT, BE, BG, CH, CY, CZ, DE, DK, EE,
`LS, TI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE, SK,
`TR), OAPI patent (BE, BJ, CK, CG, Cl, CM, GA, GN, GQ,
`GW, ML, MR, NE, SN, TD, TG).
`
`(72) Inventors; and
`(75) Inventors/Applicants (for US only): HONEYMAN,
`Trevor
`[GB/GB]; Honeyman Water Limited (GB).
`ROBINSON, Kennth [GB/GB]; Honeyman Water T.im-
`ited (GB).
`
`Publ
`
`ished:
`with international search report
`before the expiration of the time limit for amending the
`claims and to he republished in the event of receipt of
`amendments
`
`[Continued on next page]
`
`(54) Title: FLUID DELIVERY SYSTEM
`
`58—~
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`(57) Abstract: A fluid delivery system is described whereby sterile liquid may be delivered cfficiently to a number of remote loca-
`tions while nevertheless maintaining a continuousfluid flow throughthe system to prevent any bacterial growth. The systemincludes
`a storage tank feeding a first pipework loop including a first pump which urges fluid through said first loop at a first pressure and
`which returns to the tank, and also includesat least one pipework branch fed from the tank and having a second pump which urges
`fluid through the branch at a second pressure downstream of the second pump. The system functions efficaciously in that a branch
`manifold terminates cach branch and a return manifold is provided in the first pipework loop. Between these two manifolds are
`connected one or more supply hoses interrupted by an offtake component which is a simple valve opening through whichthe fluid
`can be selectively delivered at the desired location. When one or more offtakes are opened, the conventional fluid flow in the hose
`whichlinks that offtake to the return manifold is reversed on account of the pressures at which the two pumps in the firs pipework
`loop and the pipework branches operate. This type of operation allows for practically 100 % diversity, i.e. that condition where as
`many or as few offtakes in the system can be opened simultaneously without any practical reduction in the availability of fluid.
`
`O03/029721Al
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`

`

`WO 03/029721 Ad
`
`_[IMITIMMTININATA TIA MITATA
`
`For two-letter codes and other abbreviations, refer to the "Guid-
`ance Notes on Codes andAbbreviations" appearing at the begin-
`ning ofeach regular issue ofthe PCT Gazette.
`
`

`

`WO 03/029721
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`PCT/GB02/04148
`
`Fluid Delivery System
`
`fluid delivery system, and more
`This invention relates to a
`patticularly to a hygienic fluid delivery system, the construction
`of which requires careful planning and analysis to ensute that
`the resulting system has minimal
`stagnancy of flow during
`opetation and
`that bacteria growth is minimised if not
`eliminated entirely. The
`types of
`fluid
`delivery
`systems
`hereinafter described are typically provided in a wide variety of
`plant,
`including Research & Development facilities generally,
`laboratories,
`silicon wafer manufacturing plants, breweries,
`pharmaceutical manufacturing facilities, and any installation
`whete a plurality of sources of sterile water or other liquid may
`be required in a number of different locations remote from a
`supply tank for storing the water or other liquid.
`
`Although the following description is provided with almost
`exclusive teference to hygienic fluid delivery systems which
`deliver so-called Water for Injection (WFI), Purified Water (PW)
`and the like, it will be instantly appreciated that the invention
`has far wider application and may be applied to deliver any
`liquid to a predetermined location remote from a storage vessel
`through distribution pipework.
`
`It is also to be appreciated by the reader that the word “sterile”
`and cognate exptessions
`as used hereinafter
`is not
`to be
`construed in its literal sense and includes liquids having a
`bacteria, germ ort other contaminant content reduced beneath a
`desited level so that the said liquids are safe ot suitable for a
`patticular procedure.
`
`in their
`the delivery of sterile fluids,
`for
`systems
`Current
`simplest form, consist essentially of a storage vessel supplied
`intermittently ot continuously with a sufficient volume of pre-
`
`

`

`WO 03/029721
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`
`2
`
`sterilised fluid. A system of steel pipework is routed through the
`premises,
`for example a clinical
`laboratory, wherein WFI is
`required, said pipework being for the most part conventionally
`concealed in the ceiling of each room through which said
`pipework passes and descending from the ceiling only in those
`locations either where operatives are likely to regularly requite a
`source of WFI or
`alternatively in locations
`conveniently
`accessible by a number of operatives working proximate said
`location. The pipework is routed through said premises and
`ultimately returns to the storage vessel to return any excess fluid
`thereto.
`
`There are a number of important factors which must be taken
`into account when designing a sterile fluid delivery system, but
`the most important is that the system as a whole must generally
`pteclude anylocalised stagnation of fluid, either in the pipework
`ot the storage vessel and be free from crevices or similar areas
`where bacteria could become trapped and thus allowed to
`proliferate
`
`Accotdingly the pipes ate firstly commonly welded together
`using a very costly technique known as Tungsten Inert Gas
`(TIG) autogenous welding which ensures that
`the butt
`joints
`between adjacent sections of pipe are secured to one another
`without introducing unwanted contaminants into the passageway
`within the pipes and ensuring that
`the join is as smooth as
`possible internally. Furthermore the interior sutface of the
`various pipes which ate joined together throughout the system is
`important in that said interior surface must be as smooth as
`possible and any bends in the pipes must preclude the formation
`of eddy currents during fluid flow therethrough.
`It will be
`appreciated that eddy currents give rise to localised volumes of
`fluid which ate effectively stationary, and thus the temperature
`of these volumes can quickly drop to a level at which bacteria
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`WO 03/029721
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`3
`
`most teadily thrive with the result that the sterility of the system
`as a whole is prejudiced.
`
`adjusted
`Secondly, the operating temperature of the system is
`and maintained
`to ensure that any bacteria (for example
`mesophilic
`bacteria
`such
`as
`gram-negative
`pscudomonas
`commonly present
`in water)
`are
`either ptevented from
`multiplying or are actually eliminated. A common temperature
`for WFI systems is 80°C and to prevent any gradual reduction of
`the fluid temperature over time, a heater is commonly connected
`into the system.
`
`It is to be mentioned that PW and other hygienic fluid systems
`can be operated at ambient temperatures, so much greater care
`and attention nceds to be given to the construction of these
`types of systems which on account of the operating temperature
`ate much more prone to bacterial proliferation.
`
`Thirdly, it is important that a turbulent, as opposed to a laminar
`flow characteristic is developed within all sections of
`the
`pipework again to minimise the risk of bacteria proliferation.
`Fort example, in both laminar and turbulent fluid flows, it is well
`known that the velocity of the fluid immediately adjacent a solid
`sutface is minimal if not zero, whereas the velocity of fluid
`remote from such a surface is much greater. Hence the majority
`of the volumetric flow through a pipe is achieved through the
`middle of
`the pipe whereas only a
`comparatively small
`percentage of flow is attributable to the fluid moving proximate
`the interior surfaces of said pipe. This slow moving or stagnant
`fluid has
`the tendency to cool and thus not only are the
`conditions for bacteria proliferation improved adjacent to the
`interior surface of the pipe, but the fact that the fluid is either
`moving very slowly or not at all further increase the likelihood
`that bacteria will find a site on the pipe surface to germinate.
`
`

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`WO 03/029721
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`
`Turbulent fluid flows within sterile fluid delivery systems are
`desirable because velocity profile of the fluid proximate the
`interior surface of the pipe increase significantly more sharply
`than that of an equivalent laminar flow and the risk of bacteria
`proliferation and germination
`is
`thus mitigated. Biofilm
`formation on the internal surfaces is discouraged by such fluid
`
`velocities.
`
`However, it is well known in fluid dynamics that the existence
`of turbulent flows within pipes depends on, among other things,
`the diameter of
`the pipe, and the velocity of
`fluid flow
`therethrough. In general, to the development of turbulent flow
`in pipes of a larger diameter requires a significantly larger fluid
`velocity than required to establish turbulent flow in smaller
`diameter pipes.
`
`the storage vessel
`is necessary to ensure that
`it
`Fourthly,
`containing the WFI is recharged over a predetermined period of
`time,
`for example every two hours. Moreover,
`the system
`opetates
`continuously so
`that
`the storage vessel
`is being
`continually emptied and simultaneously recharged to avoid any
`stagnation of fluid therein, and the time petiod is merely an
`indication of the length of time which would be taken to empty
`to the
`storage vessel
`completely under normal operating
`conditions without any simultaneous recharge.
`
`the systems with which this
`It will also be appreciated that
`invention are concerned may have many tens of outlets or so-
`called offtakes usually connected in seties as an entire laboratory
`ot building may need to be served by a single fluid delivery
`system. The diameter of the pipes commonly used in such
`systems may be of the ordet of 1-2% inches (25-64mm), and to
`
`

`

`WO 03/029721
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`
`5
`
`ensure a turbulent flow within such a pipe the flow velocities are
`typically between 1-3m/s.
`
`In order to develop such a flow velocity, substantial and thus
`costly pumping apparatus
`is
`required, and when it
`is also
`considered that a number of different offtakes may be in use
`simultaneously,
`dynamic
`control
`of
`this
`pump
`and/or
`alternatively some means of pressure regulation is
`required.
`Conventional Fluid delivery systems must possess an ability to
`deliver
`fluid
`through
`a
`number
`of
`off-takes
`opened
`simultaneously while nevertheless operating satisfactorily when
`none of the offtakes are in use,
`for example overnight. The
`inherent disadvantage of series-type systems, in which a plurality
`of offtakes are connected in seties such as described, is that the
`opening of more than a few offtakes simultaneously can have
`detrimental effect both on the flow characteristics and the
`
`the.
`the correct flow and pressure at
`ability to draw water at
`various uset offtakes. The number of offtakes which can be
`opened simultaneously in a system expressed as a percentage of
`the total number of offtakes in a system is known as
`the
`diversity.
`
`Various different pipework loop and sub-loop configurations
`having different benefits and effects on diversity have been
`proposed.
`
`Referring now to Figures 1, 2, 3, and 4 which show different
`fluid delivery systems of prior art configuration, each of these
`systems
`shows
`a
`storage vessel 2 with which pipework 4
`communicates to both feed offtakes 6 which are embodied most
`simply in an openable valve and to return excess fluid to the
`storage vessel at 8.
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`

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`
`Each of the systems shown in the Figures comprises at least one
`pump 10 and in the case of Figure 2 a second pump 12, each of
`which urges fluid through the pipework around the system in a
`flow direction 14.
`
`It can be seen from Figure 1 that the pipework is sloped at 16
`between off takes and this is a common feature of such systems
`to allow for drainage of the fluid from the system for cleaning
`purposes. A heater 18 and a pressure regulating valve 20 ate also
`provided in series with the various offtakes 6 and it will be
`appreciated that this simple series system functions in a very
`similar manner to a simple series electrical circuit, with the
`pump corresponding to a soutce of potential difference,
`the
`offtakes corresponding to resistances dissipating power and the
`flow rate corresponding to the current. Indeed the analogy can
`be extended in the cases of Figures 2, 3, and 4 which effectively
`show parallel circuits.
`
`The importance of this analogy is that as further offtakes are
`added into a particular loop, the fluid flow which the system is
`capable of delivering through each of the offtakes when open is
`reduced depending on the number of offtakes in that loop. This
`is
`identical
`to
`the
`reduction in brightness of
`lightbulbs
`connected in seties in an electrical circuit as more and more
`lightbulbs are connected.
`
`a multiple loop
`2 which shows
`case of Figure
`In the
`artangement, a second pump 12 drives fluid through a second
`loop of the system and effectively provides sufficient
`flow
`through said loop to feed the various offtakes in that loop. In
`the case of Figure 3, a sub-loop or true parallel arrangementis
`shown, and in the case of Figure 4 a more complex main
`loop/sub loop artangement is shown wherein four separate sub
`loops 22, 24, 26, 28 are fed from a main loop 30. Each of the
`
`

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`WO 03/029721
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`7
`
`sub loops is provided with a diaphragm valve 32 immediately
`after the join to the main loop, and additionally Constaflo™
`flow regulating valves 34 are provided on each of the sub loops,
`at the most remote end of the main loop, and on a return loop
`36 which links the main loop immediately after the pump 10 to
`the stotage vessel 2. Without unnecessary description and
`analysis of the working of this arrangement,
`the diaphragm
`valves, flow regulating valves and return loop are all provided
`with a view to increasing the effective diversity of the system as
`a whole and to ensute correct hydtaulic balancing of the system.
`
`The fundamental disadvantages of the systems described other
`than their limited ability to operate at maximum diversity are
`ptimarily related to the perceived permanent nature of the
`construction. For
`instance,
`in order
`to deliver
`a sufficient
`quantity of fluid around the system, the pipes must be of large
`diameter which both increases
`the cost of materials
`and
`construction. Stainless steel pipe sections currently used in the
`construction of such systems typically are provided in only 6m
`lengths which necessitates a considerable amount of welding and
`increases the tisk of areas of bacterial germination around the
`system due to
`crevices introduced through such welding or
`alternative jointing procedutes.
`
`In the event that an additional offtake is required in an already
`installed system, it is very difficult and/or costly to modify the
`system, but perhaps most
`importantly the disruption to the
`system caused by modification can be severe. For example, the
`insertion of an additional offtake would necessitate a
`full
`draining of
`the system, opening the system to insert
`the
`additional pipework
`and offtake
`tequired,
`together with
`subsequent
`resterilisation and te-chatging. Furthermore,
`the
`additional offtake could foreseeably necessitate a larger pump
`and additional flow and pressure regulating components. It has
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`

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`WO 03/029721
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`
`8
`
`been estimated that the average cost of installation of a fluid
`delivety system is approximately £200 pet metre and it will thus
`be appteciated that these systems can significantly increase the
`cost of ptemises construction. The welding process is also
`subject
`to tigorous and costly inspection and qualification
`procedures as part of the regulatory traceability requirements of
`HM Medicines Inspectorate and the like.
`
`is an object of this invention to provide a fluid delivery
`It
`system whose effective diversity is above 90% and preferably
`approximately 100% but which is significantly less expensive
`than prior art systems to construct ,
`install, and inspect and
`subsequently certify.
`
`It is a further object of the invention to provide a system which
`can be installed with the minimum numbet of crevices and
`imperfections in the interior surface of the pipework through
`which the fluid flows, and additionally to offer the possibility of
`installing a substantially crevice-free system, at
`least
`in ‘the
`pipework coupling the offtakes to the pumping room. It is a
`further object of the invention to provide a system with as few
`joints between respective sections of pipework as possible.
`
`According to the invention there is provided a fluid delivery
`system comptising a storage vessel for fluid which feeds a first
`pipework loop including a first pump which urges fluid through
`said first loop at a first ptessute and which ultimately returns to
`said vessel, said system including at least one pipework branch
`fed from said storage vessel or said first pipework loop, said
`pipework branch including a second pump which urges fluid
`through said pipework branch at a second pressure downstream
`of said second pump, characterised in that each pipework branch
`terminates in a branch manifold having at least a fluid inlet and
`one ot more fluid outlets to the latter of which are connected
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`

`

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`9
`
`one ot more hoses which feed one ot mote offtakes from which
`fluid can be drawn from the system, and in that for each branch
`manifold there is
`a cotresponding return manifold in fluid
`communication with said first pipework loop to which said
`offtakes are connected by further hoses such that fluid can flow
`from said branch manifold through said hoses and thence
`through said return manifold ultimately being returned to the
`tank when the offtakes
`are closed,
`said first and second
`pressures being both above atmospheric pressure such that the
`opening of said one or more offtakes, and thus the opening of
`said system to atmospheric pressure at one ot mote locations
`causes the direction of fluid flow to reverse in the one or more
`hoses which connects said one or more opened offtakes with the
`retutn manifold, said one ot mote opened offtakes thus being
`supplied with fluid from both the branch manifold and the
`return manifold.
`
`Most preferably,
`vessel.
`
`the branch manifold is fed from the storage
`
`Ideally the branch and return manifolds have at least a fluid inlet
`and one ot mote fluid outlets, said branch and return manifolds
`being disposed downstream of said first and second pumps with
`fluid communication between said manifolds being achieved by
`at
`least one hose connectable to fluid outlets on respective
`manifolds and including one ot more offtakes thus allowing
`fluid flow from the storage vessel through the pipework branch,
`branch manifold, hose, return manifold and first pipewotk loop
`ultimately returning to said storage vessel and permitting fluid
`offtake at a desired location.
`
`Preferably, said retutn manifold is provided with a fluid inlet
`and a ptimary fluid outlet
`to allow for connection of said
`manifold within the first pipework loop and a plurality of
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`10
`
`to which hoses having offtakes may be
`secondary outlets
`connected to allow for fluid communication with the branch
`
`manifold.
`
`Further preferably the branch manifold is provided with a fluid
`inlet and only secondary outlets to which hoses having offtakes
`may be connected such that the fluid flowing into said branch
`manifold is urged into one otf more hoses.
`
`Preferably the fluid pressure within the return manifold is
`greater than the fluid pressure in the branch manifold, and most
`pteferably both these pressures are above ambient atmospheric
`pressure such that the opening of an offtake opens the fluid
`within to atmospheric pressure and the fluid flow direction in
`the length of hose between said offtake and said return manifold
`teverses and both manifolds urge fluid towards
`said open
`offtake.
`
`hose
`of
`plurality
`a
`circumstances,
`pteferable
`In most
`connections ate made between the branch manifold and the
`return manifold, each connection consisting of a first hose, one
`end of which is connected to one fluid outlet
`the branch
`manifold and the alternate end of which is connected to an
`offtake, a second hose having one end connected to the offtake
`and the alternate end connected to a fluid outlet of the return
`manifold. Most preferably,
`each hose connection between
`branch and return manifolds consists only of a single offtake,
`but alternately, each connection may consist of first and second
`hoses, ends of which are connected to the branch and return
`manifolds
`tespectively, alternate ends of
`said hoses being
`connected to first
`and second primary offtakes,
`and the
`connection further comprising one or mote secondary offtakes
`interconnected by intermediaty hoses between said first and
`second ptimaty offtakes and second secondary offtakes.
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`

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`
`Further preferably each hose is made of a flexible polymetic or
`plastics material such as PTFE.
`
`Preferably, the hose diameter is in the region of 5-25mm.
`
`least one of the first or second pumps is
`Most preferably at
`dynamically controlled depending on the fluid pressure within
`the respective return ot branch manifold, and most preferably
`the pump driving fluid through the first pipework loop is
`dynamically controlled depending on the instantaneous fluid
`requirements of the system,
`i.e.
`the number of offtakes which
`are open at any one instant.
`
`Most preferably only the second pump is dynamically controlled
`depending on the fluid pressure within the respective return and
`branch manifolds.
`
`The system described above has the surprising advantage that
`the opening of any offtake provided on any particular hose
`connection between the manifolds causes
`a
`reversal
`in the
`direction of fluid flow in the hose section from the return
`manifold to the said offtake. Such flow direction reversal
`is
`achieved because the fluid pressure developed in the return
`manifold is greater than the pressure developed in the btanch
`manifold and thus the fluid is urged through the offtake (which
`is effectively at atmospheric pressure once opened) along both
`sections of hose linking the offtake to said manifolds.
`
`The system has many attendant advantages resulting from the
`novel atrangement described, particularly including
`1.
`lower cost of installation and associated validation
`
`
`
`2. site-wide welding and_theelimination of need for
`associated hazards of this process;
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`

`

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`
`facility for installation by non-specialist contractors (as the
`3.
`hoses and offtakes may be installed by for example electrical
`cable installers);
`4.
`easy relocation/isolation of individual offtakes;
`5.
`future pte-cleaned offtakes can be easily added to the
`spate manifold secondary outlets and brought on-line without
`interruption to the live existing system;
`6.
`offtake hoses can be individually sterilised;
`7.
`hoses can be drained by (sterile) air or gas being blown
`therethrough thus avoiding extra costs
`for
`routing gravity
`drainage, and
`8.
`hose sterilisation can be achieved by a number of methods,
`such as chemical recirculation, steam out, hot sterile air (160°C),
`
`ozone.
`
`that provided the
`important advantage is
`the most
`Perhaps
`pumps ate effectively dynamically controlled, the diversity of the
`system remains at almost 100% as more and more offtakes are
`simultaneously opened. The only limit to the number of offtakes
`which can be opened simultaneously without any appreciable
`flow reduction therethrough is the diameter of the pipes and
`manifolds through which the fluid is urged by the pump (and
`thus the volume of fluid which can be delivered to the manifolds
`
`by said pumps).
`
`A specific embodiment of the invention is now described by way
`of example with reference to the accompanying drawings
`wherein
`
`Figures 1-4 schematically show fluid delivery systems of prior
`att configuration,
`
`Figure 5 schematically shows a fluid delivery systems according
`to the invention,
`
`

`

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`13
`
`Figures 6, 7 show details of possible offtake shroud assemblies,
`
`Figures 8, 9 show perspective views of possible loop and branch
`manifold assemblies,
`
`Figures 10, 11 show schematically possible offtake assemblies.
`
`an alternative arrangement
`12 shows
`Figure
`according to the invention.
`
`for
`
`a
`
`system
`
`there is shown a fluid delivery
`Referting firstly to Figure 5
`system 50 comprising a storage vessel
`feeding pipework 52
`which divides into a pipewotk loop 54 and a pipework branch
`56. The loop 54 ultimately returns to the storage vessel 52 at 58
`to recharge said vessel with fluid pump atound the system.
`
`In each of the loop 54 and the branch 56 are provided pumps
`60, 62 respectively which are located upstream of a return
`manifold 64 and a branch manifold 66 each of which has at least
`a ptimary fluid inlet 64A, 66A and a numbet of secondary fluid
`outlets 64B, 66B to which hoses 64C, 66C can be connected.
`Each of the hoses 64C, 66C is connected to an offtake which
`essentially comprises an openable valve which when closed
`allows fluid by pass from the hoses 66C to 64C.
`
`In a preferred embodiment, the pumps 60, 62 ate dynamically
`controlled by coupling the pump motot
`to manifold pressure
`sensors
`schematically represented at 70, 72 in response to
`changes in fluid pressute inside the manifolds 64, 66. In this
`manner,
`the fluid flow and pressure can be automatically
`maintained at required levels when one or mote of the offtakes
`is opened to deliver fluid therethrough. It is to be mentioned
`that this arrangement provides the most accurate control, but
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`once the opetating limits of a particular system ate determined it
`is mote likely that only a single pump need be dynamically
`controlled.
`
`there may optionally be
`Downstream of the return manifold,
`provided a sanitisation unit and/or a heat exchanger 73, 74 to
`ensute
`that
`the desited temperature is maintained during
`operation. Thereafter fluid is returned to the vessel 52 from
`which it is later pumped around the system.
`
`Example system operating conditions include a minimum flow
`rate of 100litres/min in the pipework branch, a maximum flow
`rate of 160litres/min, a pressure of 6bar in the branch manifold,
`and a minimum flow rate of 45litres/min in the pipework loop, a
`maximum flow trate of 225litres/min and a tfetutn manifold
`pressure of 2 bar.
`
`Figure 5 also schematically shows a possible layout of the system
`in that the bulk of the apparatus used in the system is located in
`a plant room schematically defined above the dotted line 76, a
`pottion of the length of the hoses 64C, 66C which communicate
`with the offtakes and the respective loop and branch manifolds
`ate disposed in a roof or wall void represented between dotted
`line 76 and a further dotted line 78, and the offtakes 68 are
`optionally connected at the end of shrouds secured to the toof
`ot walls to conceal the hoses.
`
`Examples of such shrouds 80, 82 and offtakes 84, 86 are shown
`in Figures 6 and 7.
`
`Figures 8, 9 show possible embodiments of the return manifold
`64 and btanch manifold 66. The manifolds are different because
`
`fluid is required to flow through the return manifold 64 from a
`ptimaty inlet 64A to a primary outlet 64A’
`in the direction
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`indicated at 88. There are further provided vatious secondary
`fluid outlets 64B the numbet of which corresponds to the
`number of offtakes desired in a particular system, and although
`the wotd “outlet” is used in connection with these fittings, it is
`to be appreciated that fluid in generally will only flow out of
`same when the particular offtake fed by the hose connected to
`said outlet is opened. In the alternate circumstance when the
`offtake is closed, fluid will flow into the manifold through outlet
`and be combined with the fluid flow through the manifold from
`one end to the other as indicated at 88. A pressure control
`outlet PC for dynamic pump control and a spare instrument
`access 90 are also provided.
`
`In the case of the branch manifold 66, a primary inlet 66A is
`provided, together with a number of secondary outlets 66B to
`which the hoses 66C are connected. A pressure control outlet
`PC is disposed at one end of the manifold 66 whereas the
`opposite end is blanked off at 92 to prevent any fluid escape
`through said end. In the case of the branch manifold, fluid flows
`continually through the outlets 66B regardless of whether the
`offtakes fed by hoses 66C are open or closed.
`
`there is shown a schematic
`Referting to Figures 10 and 11,
`teptesentation of an offtake having connectors 94, 96 to which
`hoses 66C, 64C ate connected to feed the offtake with fluid. A
`chamber 98 is provided which allows for fluid flow from hose
`66C to hose 64C when the offtake is closed and for
`fluid
`
`reversal in hose 64C when the offtake is opened, and this in turn
`is connected to a standard diaphragm valve or similar 100 having
`actuator 102 if necessary.
`
`A schematic sectional view of the chamber is shown in Figure 11
`and it can be seen from this figure that the flow of fluid within
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`said component may be achieved by oritice plates 104 provided
`internally thereof.
`
`' In circumstances where a uset only gradually opens a valve to an
`offtake, it is foresceable, depending on the design of the various
`components within a system, that the fluid flow velocity within
`hose 64C could merely reduce as opposed to become reversed,
`and in particular circumstances it may also ttanspite that on
`opening an offtake by a predetermined amount,
`the fluid
`velocity in the hose 64C teduces to zero, said offtake being
`supplied entirely by fluid flow to the offtake through hose 66C.
`Such operating conditions ate envisaged only transiently and
`would not prevail for any significant length of time which could
`materially affect the hygiene of the fluid within the system as a
`whole. It is also to be mentioned that these particular operating
`characteristics will
`only arise
`infrequently,
`and the most
`desirable system operation will involve the reversal of fluid flow
`direction through hose 64C.
`
`there is shown an alternative
`Finally, referring to Figure 12,
`atrangement of a
`fluid delivery system which functions
`in
`accordance with the invention.
`In the arrangement shown, a
`stotage vessel 200 is fed with a supply of purified or sterile
`watet at 202, and the vessel 200 is connected within a first
`pipework loop 204. Within said first pipework loop,
`there is
`disposed a low pressure, high volume pump 206 which causes
`fluid flow around the loop 204. The box 208 in this figure which
`surrounds
`the pump and vessel
`is
`representative of a
`site
`pumping and equipment room, and remaining boxes in dotted
`lines 210, 212, 214 are
`representative of either different
`buildings to which a supply of sterile fluid is required to be
`delivered, or alternatively different but remotely located zones
`in the same building.
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`the first pipework loop is constructed around a
`Accotdingly,
`path which approaches each zone at a suitable location. In the
`region of each zone, a branch 218 is taken from the main loop
`and feeds a pump 220 which may be dynamically controlled at
`222 accotding to instantaneous fluid usage requirements at the
`vatious offtakes, 224 required or being used in that zone at any
`time. The pump 220 delivers pressurised fluid to a branch
`manifold 226 which is connected to said offtakes